title: The effect of a low carotenoid diet on malondialdehyde-thiobarbituric acid (MDA-TBA) concentrations in women: a placebo-controlled double-blind study.
abstract: OBJECTIVE
  The purpose of the study was to evaluate the effect of a low carotenoid diet (83 micrograms Beta-carotene) on malondialdehyde-thiobarbituric acid (MDA-TBA) concentrations of nine pre-menopausal women.
  
  
  METHODS
  Subjects lived on the metabolic research unit of the Western Human Nutrition Research Center (WHNRC), where diet, exercise and other activities were controlled. Five subjects (Group C, control group) consumed a low carotenoid diet and received an additional 0.5 mg/day of Beta-carotene while four subjects (Group P, placebo group) received only the low carotenoid diet during days 1 to 60 (period 1). All subjects received 0.5 mg/day of Beta-carotene during days 60 to 100 (period 2), plus three capsules/day mixed carotenoid supplement (Neo-Life Company) during study days 100 to 120. Changes in MDA-TBA concentrations were analyzed during the study periods and between the groups.
  
  
  RESULTS
  At the start of the study (day 1), no significant difference in the MDA-TBA concentration was observed between the control (Group C) and the placebo (Group P) subjects. During period 1 (days 2 to 60), when Group P subjects consumed the low carotenoid diet without supplementation, the MDA-TBA values for Group P rose markedly and were significantly (p < 0.05) higher than the MDA-TBA values for Group C subjects who were receiving carotenoid supplementation. During period 2 (days 60 to 100) when both groups received carotenoid supplementation, the MDA-TBA values of Group P subjects were significantly (p < 0.05) reduced to the point where they were similar to the MDA-TBA values for Group C subjects.
  
  
  CONCLUSIONS
  These findings provide evidence to support the beneficial effects of carotenoids in preventing lipid peroxidation in the cells. Further studies are needed to identify the exact mechanism by which carotenoids prevent lipid peroxidation and the amount needed for normal activity.
authors.affiliation: Florida International University, Department of Dietetics and Nutrition, College of Health, Miami 33199, USA.
authors.forename: Z R
authors.initials: ZR
authors.lastname: Dixon
authors.forename: F S
authors.initials: FS
authors.lastname: Shie
authors.forename: B A
authors.initials: BA
authors.lastname: Warden
authors.forename: B J
authors.initials: BJ
authors.lastname: Burri
authors.forename: T R
authors.initials: TR
authors.lastname: Neidlinger
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008315:Malondialdehyde / Q000097:blood*; D010919:Placebos; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis*; D019207:beta Carotene / Q000008:administration & dosage*
chemical_list: D010919:Placebos; D017392:Thiobarbituric Acid Reactive Substances; D019207:beta Carotene; D008315:Malondialdehyde